Scoring script not applied with bool query

Elastic Stack Elasticsearch
1

I have a custom native scoring script (hamming distance), installed on an elasticsearch v2.3.1, and I'm applying it in my query like so:

curl -XPOST 'http://localhost:9200/myindex/_search?pretty' -d '{
      "query": {
        "function_score": {     
          "min_score": 14,
          "query":{
           "bool": {
                     "minimum_should_match": 6,
                     "should": [
                        {
                           "fuzzy": {
                              "myField0": {
                                 "value": "10110110",
                                 "fuzziness": 2
                              }
                           }
                        },
                        ...
                        {
                           "fuzzy": {
                              "myField7": {
                                 "value": "10010100",
                                 "fuzziness": 2
                              }
                           }
                        }
                     ]
                  }
          },
          "functions": [
            {
              "script_score": {
                "script": "hamming_distance",
                "lang" : "native",
                "params": {
                  "param_hash": "myhash",
                  "param_field":"myField"
                }
              }
            }
          ]
        }
      }
    }'

The problem is that the scoring script is not being applied. If I change the query type to a filtered query, then it works - the scoring script is applied, but then I can't generate this query using the Java API because filteredQuery is deprecated in favour of using boolQuerys.

Can anyone advise what I should be doing? Should I be doing bools with filters nested or something? Thanks for any help!